This invention relates to a blow molding machine and particularly to one having an improved take-out assembly which removes workpieces from the forming molds and transports them to an associated material handling device.
Blow molding machines operate by charging a mold cavity with a parison of plastic material which is heated to a semi-fluid state, and is thereafter subjected to internal pressurization through an inserted needle causing the plastic to inflate and conform to the inside surfaces of the mold cavity. Blow molding machines are used to produce numerous types of articles and have been particularly used in making containers for beverages, household chemicals, etc.
One type of blow molding machine is referred to as a vertical turntable type and has a turntable which rotates about a horizontal axis. The turntable has a number of arms, each supporting a multi-piece mold assembly. The turntable is rotated continuosly past a number of workstations. At one workstation, components of the mold assembly are separated to expose the mold cavity. Thereafter, the mold assembly passes adjacent to a discharge nozzle of a plastic extruder which charges the mold cavity with a heated plastic parison. The mold components are then clamped together and rotated to the next workstation where a fluid (eg. air) is injected into (or evacuated from) the mold to cause the charge to expand and conform to the inside surface of the mold cavity. During continued rotation of the turntable, the mold assembly is cooled to cause the plastic material to freeze and solidify. Finally, the mold assembly is opened and the finished workpiece is removed by a take-out assembly. In accordance with the prior art, take-out devices conventionally includes a hook or rod which engages the workpiece and transports it to an associated material handling system such as a conveyor. The conveyor transports the workpiece to other workstations for flash removal, labelling, filling, etc.
Although the presently available blow molding machines operate satisfactorily, there is a need to provide such machines with an improved take-out assembly which more positively removes the workpieces and more accurately positions them with respect to an associated material handling system such as a conveyor.